Page 1 of 1

carb adjustment

PostPosted: Mon Sep 17, 2012 3:19 pm
by anarchychoppers
I have a 1974 TS 250 with BVF 28 n 1-1 what is the initial adjustment on the carb? I have the throttle stop screw 4 turns out, and the slow running adjuster screw 3 turns out. I had it running and took it around the street and it the engine kept racing. I adjusted it some more and now it wont start.

What is everyone setting their carbs at. Oh it has 37 original miles

Re: carb adjustment

PostPosted: Mon Sep 17, 2012 3:39 pm
by anarchychoppers
Also what is the shift pattern on this thing? Is it 1 up 3 down? or 1 down 3 up?

Re: carb adjustment

PostPosted: Mon Sep 17, 2012 3:57 pm
by therealche
Shift pattern is one down three up. Good starting place for the slow running screw is 1.5 turns out. Throttle stop screw should be in just enough to make it tick over when warmed up. Sounds if the throttle slide might be hanging up. Make sure the cable is well lubricated, and give the slide and bore a light polish to remove any corrosion.

Re: carb adjustment

PostPosted: Mon Sep 17, 2012 4:49 pm
by anarchychoppers
Thanks, I lubed the cables once I got her back home. I also have my needle set in the 4th slot as I don't remember what it was set at before I took it apart. I thought it was the forth, the book says 3rd or 4th.

Thanks,
Ronnie

Re: carb adjustment

PostPosted: Tue Sep 18, 2012 9:20 am
by therealche
Another thing to check is there are no leaks between the carb and the inlet manifold, and the manifold and the cylinder. Always thought the TS250 engine used the BVF 30 N2-3, suppose they must have had some of the smaller carbs left over from the ES250/2s!

Re: carb adjustment

PostPosted: Tue Sep 18, 2012 11:10 am
by anarchychoppers
One more thing it says in the book the pilot setting is 2-3 turns out. What is this referring to the pilot jet inside the carburetor? The only adjustment I see is the Slow running adjuster screw & Throttle stop screw. I have also hear to drill the pilot jet to .5mm is this true or what.

Re: carb adjustment

PostPosted: Tue Sep 18, 2012 1:18 pm
by therealche
No they are refering to the slow running screw. I have never drilled the pilot jet, some people find it helps reduce jerking when closing the throttle but with a well adjusted rear chain I never found it that much of a problem